provide permanent, secure installation. 3. Spacing of mounting adhesive shall not exceed: a. Horizontal Surfaces: 1 1 inches ([ 1 mm) on center. b. Vertical Surfaces: [ 1 inches (1 1 mm) on center; provide temporary shims until adhesive cures. 4. [Fasteners] [Grout] [Hardware]: [ 5. Install surfacing plumb, l